As the pediatric malignancy cure rate approaches 80%, the growing population of childhood cancer survivors now comprises 1 in 640 young adults 20 to 39 years of age. Of the 13,725 participants in the Childhood Cancer Survivor Study (CCSS), North America's largest survivor cohort, 26% are now 41 years of age, and 2.8% are 51 years of age. While the late effects of childhood cancer and its treatment have been studied extensively, we know very little about the self-perceived health care needs or the long-term health experience of these adult survivors. Pediatric cancer therapies can affect all aspects of a survivor's life: physical, psychological, social, economic, and existential. The impact of therapy is likely to precipitate different survivor needs at different time points, owing to the heterogeneity of childhood cancers, treatment exposures, survivor behaviors, and informed access to health care. Perceptions of survivors'health-related needs have been shaped largely by investigators'research interests. No study has addressed the self-reported needs of childhood cancer survivors older than 40 years or comprehensively addressed the health-related needs of survivors aged 25 or older. Moreover, the under-representation of minorities and rural residents has not been addressed. To prepare for a large-scale, ongoing, longitudinal needs assessment of the rapidly growing population of childhood cancer survivors, we propose a feasibility study that will use the unique resource of the CCSS cohort to: 1) examine the construct validity, short-term stability, internal consistency, and item- response performance of a multifactorial needs assessment self-report instrument for childhood cancer survivors;2) inform strata selection for the larger study and increase the diversity of the target sample by oversampling minority and rural-dwelling survivors;3) preliminarily describe the met and unmet needs and their covariates in a large, stratified, random sample of childhood cancer survivors;and 4) evaluate the sample selection methods, length of time to complete recruitment, and response rates. The results of this feasibility study will inform and lay the foundation for longitudinal surveys that will provide the basis for models of comprehensive cancer care that specifically target the needs of aging childhood cancer survivors. PUBLIC HEALTH RELEVANCE: The pediatric malignancy cure rate is now nearly 80%, and the growing population of childhood cancer survivors comprises 1 in 640 young adults 20 to 39 years of age. Within the Childhood Cancer Survivor Study (CCSS), North America's largest survivor cohort, 26% are now e 41 years of age, and 2.8% are e 51 years of age. While the late effects of childhood cancer and its treatment have been studied extensively, we know very little about the self-perceived health care needs or the long-term health experience of these adult survivors. The results of this feasibility study will inform and lay the groundwork for longitudinal surveys that will provide the basis for models of comprehensive cancer care that specifically target the needs of aging childhood cancer survivors.